Convertible fan unit



FIG. 1 is a front, top and left side perspective view of a convertible fan unit, set up to function as a window fan, showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a right side elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a left side elevation view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof;

FIG. 8 is a front perspective view thereof shown set up as it would be to function as a floor or table fan; and

FIG. 9 is a rear perspective view of FIG. 8.

The broken-line showing of sliding panels in FIG. 1 is for illustrative purposes only, and forms no part of the claimed design. 

The ornamental design for a convertible fan unit, as shown and described. 